At present, known in the art are chemcial compositions, serving the same purpose which generate oxygen suitable for breathing. Described in a French Pat. No. 2,164,988; Cl. A62d 9/00 is a chemical composition in the form of pressed bricks which generate breathing oxygen. The composition in parts by weight is as follows: sodium chlorate, 92; a 1:1 mixture of silicon and magnesium, 3; cupric oxide, 1; nickel oxide 4. The ingredients of a specified grading are mixed up, heated to 200.degree. C. and pressed. The bricks thus produced are used as generators of breathing oxygen on being heated in any way, for the reaction of oxygen liberation must be induced by an increase in temperature. The liberation of chlorine during the reaction of decomposition is a disadvantage, for much of the composition goes to neutralize the chlorine.
Another known composition of the same kind is one due to T. L. Thompson which is disclosed in U.S. Pat. No. 3,702,305. It is composed basically of an oxygenic substance--chlorate of an alkali metal or sodium peroxide--taken in an amount between 1.0 and 20 wt.% (or a mixture of sodium oxide and sodium peroxide, 0.5 to 20 wt.%), perchlorate of an alkali metal, 15 wt.% and an activator containing sodium chlorate and sodium oxide (or a mixture of oxides) as a catalyst. The reaction between the sodium oxide and sodium chlorate is an exothermic one and so is the reaction of oxidation of the sodium oxide. The heat thus liberated brings about the decomposition of the oxygenic substance which is sodium chlorate decomposing at 350.degree. C.
The disadvantage of Thompson's composition is the possibility of liberation of free chlorine which is toxic and calls for employing efficient absorbers to keep the breathing mixture pure. This composition also lacks a moisture-containing component liberating moisture which is required to activate the regenerative composition based on potassium superoxide during the initial period of operation of the breathing apparatus. The composition is also unsuitable for use at ambient temperature to -5.degree. C.